The invention is related to a method of forming the resin cover lens of LED assembly, and more particularly to a transparent material is used as the mold for forming the resin cover lens of LED assembly, so electron-beam (EB) or ultraviolet ray (UV) can pass through the transparent mold and quickly cure the resin materials into lens.
Traditional light emitting diode assembly (abbreviated to LED assembly) can be designed with various assembly structures according to application or structural requirements, such as Taiwan Patent Nos. M297481, M294096, 1246787, 1246779, M283326, M283312, M281294, M268724, M297046, M294808, M291602, M291085, M289908, M289521, M288974, M288005, M287503, 200629598, 200628727, 200629598, 200635085, 200414558 and U.S. Patent Pub. No. US2006/0105485A1 et al. As in FIG. 1, a traditional LED assembly 1 mainly comprises: one base 10 to support LED chip 11 and electrically connect LED chip 11 to light LED chip with external power source; one or several LED chips 11 to light with external power source; and one or multiple layers of resin cover lens 12 made of transparent resins to cover the base 10 and LED chip 11 and make the base 10 and LED chip 11 into a LED assembly 1, and also make LED chip 11 to light through the resin cover lens 12 outward; wherein the cover lens 12 are usually made of transparent or light permissive resins and located on the supporting plane of the base and able to cover the LED chip, forming a LED assembly structure. Further, the LED assembly can be designed with cover lens of different properties, i.e. the cover lens can be designed into different structure or lighting mode, such as using phosphor substance in resin to generate white light or designing different surface patterns to form different lighting patterns, or designing inner, outer or multiple-layer lens.
A normal method of forming a LED assembly is as follows: providing a molding tool with cavity in the shape of the cover lens; having the cavity face up and fill in liquid transparent resin, usually PU (Polyurethane), epoxy, silicon, acrylic resin, copolymer, to form the lens; placing the LED chip or the electrically connected LED chip and base at the entry of the mold cavity, so the supporting plane of the base and the LED chip can be partially or completely soaked into the liquid transparent resin, i.e. the liquid transparent resin can coat the supporting plane of the base and the surface of the LED chip; heating up the mold and the resin inside, for example, in the oven, to thermally cure the resin; then taking out the entire article from the mold to complete the LED assembly process. However, the mold in a traditional method of forming the LED assembly is usually made of metal, which does not have light transparency, so only the liquid transparent resin at the cavity entry is exposed to a limited extent. Moreover, the LED chip or its combination with the base is located with other tools at the cavity entry could cover some of the limited exposure area, so the exposure are a of the liquid transparent resin is further decreased, which makes it difficult for EB or UV radiation to cure the resin. Thus, a traditional LED assembly process would place the mold filled with the liquid transparent resin in an oven, such as baking at 120° C. for one hour or above. The entire curing process is lengthy and hinders the mass production of LED assembly.